160 EDWIN 8. GOODRICH 
even when these have reached full size, there can be little doubt 
that the presence of the gregarine checks its deposition. Never 
have we observed full-sized eggs without parasites in which this 
layer was not present. 
Emergence of parasite from egg.—When the tro- 
phozoite has completed its growth it emerges from the egg-shell 
by around hole, whichis probably the enlarged original opening 
through which it entered, or at least formed afresh in the same 
place (figs. 5, 8). The gregarine first pushes out its poimted 
' ‘tail’ end, the rest of the body following after. 
Fate of parasitized egg.—Assoonas the parasite has 
thus abandoned the egg, leaving a large space partially sur- 
rounded by the emaciated host-cell and communicating with the 
exterior by an aperture of considerable size, leucocytes from 
the coelomic fluid make their way in (figs. 8, 11, 12). They 
gather in large numbers in the cavity, and proceed to attack the 
already depleted ovum, the cytoplasm of which becomes 
vacuolated. Strange thread-like structures, which stain im 
acid-fuchsin, are now visible round the edge of the egg (th., fig.12) 
before its final breaking up. 
The free trophozoite.—the full-grown trophozoite 
free in the coelomic fluid is usually pear-shaped, the epimerite 
being at the blunt end. Asa rule the nucleus is provided with 
two conspicuous karyosomes, but additional small granules 
may be present. Often the gregarines hang together in groups, 
sometimes in masses of ten or twelve individuals. 
Association and spore-formation.—The associa- 
tion of two trophozoites is terminal (fig. 13), the ‘ head ’ end of 
one penetrating deeply into that of the other in the manner so 
characteristic of the genus Gonospora (8, 4). At the extremity 
of the embedded epimerite may be seen in sections a cap of 
dense substance tipped with a deeply-stainmg granule, possibly 
of nuclear origin (fig. 14). At this stage, before the formation of 
a cyst, the two associates can still be separated by pressure. 
As soon as the cyst wall is secreted round the pair their opposed 
faces flatten out. Gamete formation and syngamy then take 
place as usual in these gregarines. 
